7 replies to this topic

[Supierce]

Chemo-enzymatic Synthesis of Isotopically Labeled Nicotinamide Ribose

 

As a cofactor for numerous reactions, NAD+ is found widely dispersed across many maps of cellular metabolism. This core redox role alone makes the biosynthesis of NAD+of great interest. Recent studies have revealed new biological roles for NAD+ as a substrate for diverse enzymes that regulate a broad spectrum of key cellular tasks. These NAD+-consuming enzymes further highlight the importance of understanding NAD+biosynthetic pathways. In this study, we developed a chemo-enzymatic synthesis of isotopically labeled NAD+ precursor, nicotinamide riboside (NR). The synthesis of NR isotopomers allowed us to unambiguously determine that NR is efficiently converted to NAD+ in the cellular environment independent of degradation to nicotinamide, and it is incorporated into NAD+ in its intact form. The versatile synthetic method along with the isotopically labeled NRs will provide powerful tools to further decipher the important yet complicated NAD+ metabolism.

 

Edited by Supierce, 29 April 2018 - 11:30 AM.

[APBT]

LINK TO ABSTRACT:  http://pubs.rsc.org/...ob/c8ob00552d#!divAbstract

LINK TO FULL TEXT:  http://sci-hub.tw/10.1039/C8OB00552D#

[Supierce]

Thanks APBT - I forgot to post the link!  

[Harkijn]

For us NR users this is very encouraging. I had never expected that small amounts of NR would drive NAD so much higher in such a short time. I hope some knowledgeable posters here scrutinize the paper.

(yes, I am aware that higher NAD is not automatically healthier. )

[Hebbeh]

Another study of incubated cell cultures in a petri dish and hardly representable of what may occur in the complex biological environment of the entire organism.  There is still serious doubts about NR surviving the digestive tract intact (which is not addressed entirely) and as such, whether any NR would be available at the cellular level for intact delivery without being reassembled in vivo via the constituents nicotinamide and ribose and if so, similar results would be had from simply supplementing said constituents individually ready for assembly in the cellular biology.

[able]

From what I could understand, this is showing that in cells:

 

1. some NR is degraded to NAM, but most NR is converted to NAD+

 

2. NR can "transfer" between cells

 

'So the creation of 13C-NAD+ is probably a result of “base exchange” '

 

 

It seems both are positive outcomes for any NR that is available to cell.  But, does this have any implication for the fate of NR in the GI tract?

 

Or is it just saying that any NR that has made it thru the GI tract intact, will most likely convert to NAD+ rather than NAM?

 

(oh, I see Hebbeh beat me to the question)

Edited by able, 29 April 2018 - 06:32 PM.

[Harkijn]

 I agree, sofar I can only see additional questions.  Stands to reason, this really is a first attempt ( I know of) of tracing NR by labeling.

[MikeDC]

 I agree, sofar I can only see additional questions.  Stands to reason, this really is a first attempt ( I know of) of tracing NR by labeling.

 

It is hard to imagine that the small amount of NR that gets into the blood stream can cause so much anti aging effect many people experience

compared to NAM and Niacin. But the effects are real. So it makes it really important to find ways to increase bioavailability of NR so we either get better effects or lower the dose.